Shaking the Family Tree

What to Do When Heart Disease is a Family Affair

Features like blue eyes or curly hair are clear evidence of the traits passed down through families. The genetics that carry cardiovascular concerns from one generation to the next are not as obvious, but awareness is growing as scientists make progress cracking the genetic code.

Researchers now know that some genes and genetic mutations or patterns can be linked to certain diseases, including cardiovascular disease. For example, researchers involved with the renowned
Framingham Heart Study have found a particular gene variation that may contribute to high blood pressure in men and another that appears to increase heart disease risk in general.

While physicians have long attempted to track inherited heart disease through discussing family history with patients or reviewing medical records, the sequencing of the human genome and medical advances have made genetic research much more commonplace.

"We welcome patients - with or without a referral - to the genetic clinic, where we are also involved in clinical and stem cell research, as well as drug screening," says
Saumya Das, MD, PhD, a researcher and cardiac electrophysiologist at the CVI.

The clinic's services include facilitating genotyping, interpreting the results, screening family members and making recommendations for treatment and follow-up, as well as management of care when disease is diagnosed. In addition, Dr. Das and his colleagues implant defibrillators and pacemakers that may be recommended for certain inherited diseases.

When Genetic Testing is Needed

Indicators to watch for that would make an individual a potential candidate for genetic testing include:

An abnormal electrocardiogram (EKG)

Prior experiences of blackouts or sudden loss of consciousness

A family history of early sudden death, particularly at age 60 or younger

A diagnosis or family history of

Cardiomyopathies - disorders of the heart muscle

Arrhythmias - abnormal heart rhythms that may be inherited, such as atrial fibrillation, long QT syndrome and Brugada syndrome

Marfan's syndrome - a disorder of the connective tissue that may affect the aorta, among other organs

Systemic diseases that may affect the heart, such as muscular dystrophy or skeletal myopathy

The Process for Genetic Testing

"Genetic sequencing is much more available for individuals today than it was in the recent past," says Das. "Just five years ago, sequencing genes for an individual would cost about $20,000. Now it's about $5,000, and in most cases, we can deflect payments to Medicare and insurance providers, so most patients have a minimal out-of-pocket expense."

"The first course of action is likely an electrocardiogram (EKG) and echocardiogram to look at electrical and structural changes. A treadmill stress test may also be done to see what physical limitations are present," says clinic cardiologist
Matthew P. Coggins, MD, another CVI researcher with expertise in inherited cardiomyopathies. "If abnormalities or certain risk profiles are found, genetic testing may be recommended."

Coggins said genetic testing or sequencing is accomplished through a blood test.

"If a genetic mutation is found, we know that a hereditary pattern may exist, and family members can then be screened as well," he explains.

The finding of a known genetic mutation that may explain the abnormalities seen in the patient has implications for management of the patient and his or her relatives.

Protecting the Next Generation

"There's great potential to proactively investigate children when parents are found to be at risk," says Das. "When young children are involved, we partner with Children's Hospital. In fact, once we have obtained the sequence information for the patient, we can see the patient here at BIDMC and have their children seen by our colleague, Dr. Abrams, at Children's Hospital in the same day."

He adds, "We are providing a lifelong service for families at risk. We have patients we've seen for years, and now we are tracking their siblings and children."

Healthy Living and Medical Intervention Critical

The genetics of cardiovascular disease are complex. For example, a person may have mutations in genes that increase risk or other mutations that decrease risk. This could cause one family member to experience severe symptoms of an inherited disease or no symptoms at all, compared to a relative with the same mutation.

Having a genetic risk does not mean you will develop a particular condition, but rather that you have a higher chance of developing it than if you did not have the risk.

While you can't change your genetics, healthy living can modify disease progression. And, physicians can also help you decrease risk through the use of medications or procedures that slow the advancement of heart disease.

"Clinical and genetic screenings of patients and their family members can help take the guesswork out of diagnosis," says Coggins. "Used along with preventive lifestyle choices and medical intervention when needed, patients and their families can take charge of their health and live longer, healthier lives."